The connection between mass media, public opinion and public policy has been one of the more fruitful areas of study by communication and other social science scholars during the past 40 years. However, this area remains a challenge to study because of the measurement difficulties involved in defining issues and events and then applying a methodology suitable for studying these relationships. This paper charts trends in methodological advances in this area, beginning with simple time-series analysis and the use of simple cross-lagged correlations of ranked mass media and public opinion issues (McCombs & Shaw, 1972), to the measurement of single media and public issues over time, and then to the use of Autoregressive Integrated Moving Average (ARIMA) modeling.
The methodological advances in this area suggest that scholars should approach these studies in a way that provides for a greater breadth of understanding of these dynamics (at some expense of depth). The agenda-setting and agenda-building traditions of mass communication research offer an appropriate basis for study of these dynamics. A model of agenda-opinion congruence is offered as a theoretical umbrella to provide understanding of the larger dynamics at work in the relationships of public opinion, public policy, and mass media. This model holds that public opinion plays a key role in influencing media and policy content. The model of agenda-opinion congruence also draws from the spiral of silence theory and offers the thought that under certain conditions (such as war or national crisis), the media and government are themselves influenced by the dominant public opinion and public support.
The study posits that simple, unanswerable questions of causation (i.e., "Did the government set the media and public agendas during a particular crisis?") should be avoided in complex, dynamic processes such as political elections and in war or other crisis events. In addition, this study offers a new method useful in classifying key issues and events. Additionally, the new methodology noted in this paper has the potential to reveal previously unforeseen effects, such as one called “echo reverberations,” explaining some characteristics of the beginning stages of issue/event development or the "birth" of an issue or event in media and public policy agendas.